Angular Material 7 - Sort Header

The <mat-sort-header> and matSort, an Angular Directives, are used to add sorting capabipty to a table header.

In this chapter, we will showcase the configuration required to show a Sort Header using Angular Material.

Following is the content of the modified module descriptor app.module.ts.

import { BrowserModule } from  @angular/platform-browser ;
import { NgModule } from  @angular/core ;
import { AppComponent } from  ./app.component ;
import {BrowserAnimationsModule} from  @angular/platform-browser/animations ;
import {MatSortModule} from  @angular/material 
import {FormsModule, ReactiveFormsModule} from  @angular/forms ;
@NgModule({
   declarations: [
      AppComponent
   ],
   imports: [
      BrowserModule,
      BrowserAnimationsModule,
      MatSortModule,
      FormsModule,
      ReactiveFormsModule
   ],
   providers: [],
   bootstrap: [AppComponent]
})
export class AppModule { }

Following is the content of the modified HTML host file app.component.html.

<table matSort (matSortChange) = "sortFood($event)">
   <tr>
      <th mat-sort-header = "name">Dessert (100g)</th>
      <th mat-sort-header = "calories">Calories</th>
      <th mat-sort-header = "fat">Fat (g)</th>
      <th mat-sort-header = "carbs">Carbs (g)</th>
      <th mat-sort-header = "protein">Protein (g)</th>
   </tr>
   <tr *ngFor = "let food of sortedFood">
      <td>{{food.name}}</td>
      <td>{{food.calories}}</td>
      <td>{{food.fat}}</td>
      <td>{{food.carbs}}</td>
      <td>{{food.protein}}</td>
   </tr>
</table>

Following is the content of the modified ts file app.component.ts.

import {Component, Injectable} from  @angular/core ;
import {Sort} from  @angular/material ;
export interface Food {
   calories: number;
   carbs: number;
   fat: number;
   name: string;
   protein: number;
}
@Component({
   selector:  app-root ,
   templateUrl:  app.component.html ,
   styleUrls: [ app.component.css ]
})
export class AppComponent { 
   foods: Food[] = [
      {name:  Yogurt , calories: 159, fat: 6, carbs: 24, protein: 4},
      {name:  Sandwich , calories: 237, fat: 9, carbs: 37, protein: 4},
      {name:  Eclairs , calories: 262, fat: 16, carbs: 24, protein: 6},
      {name:  Cupcakes , calories: 305, fat: 4, carbs: 67, protein: 4},
      {name:  Gingerbreads , calories: 356, fat: 16, carbs: 49, protein: 4},
   ];
   sortedFood: Food[];
   constructor() {
      this.sortedFood = this.foods.spce();
   }
   sortFood(sort: Sort) {
      const data = this.foods.spce();
      if (!sort.active || sort.direction ===   ) {
         this.sortedFood = data;
         return;
      }
      this.sortedFood = data.sort((a, b) => {
         const isAsc = sort.direction ===  asc ;
         switch (sort.active) {
            case  name : return compare(a.name, b.name, isAsc);
            case  calories : return compare(a.calories, b.calories, isAsc);
            case  fat : return compare(a.fat, b.fat, isAsc);
            case  carbs : return compare(a.carbs, b.carbs, isAsc);
            case  protein : return compare(a.protein, b.protein, isAsc);
            default: return 0;
         } 
      });
   }
}
function compare(a: number | string, b: number | string, isAsc: boolean) {
   return (a < b ? -1 : 1) * (isAsc ? 1 : -1);
}

Result

Verify the result.

Details

Here, we ve created a table. Added matSort and handles its matSortChange event.